Oncophorus virens (Hedw.) Brid., 1826

Lars Hedenäs, 2017, Scandinavian Oncophorus (Bryopsida, Oncophoraceae): species, cryptic species, and intraspecific variation, European Journal of Taxonomy 315, pp. 1-34 : 23-25

3. Oncophorus virens (Hedw.) Brid.

Fig. 9

Bryologia Universa 1: 399 (von Bridel 1826). – Dicranum virens Hedw. , Species Muscorum Frondosorum: 142 ( Hedwig 1801). – Aongstroemia virens (Hedw.) Müll.Hal. , Synopsis Muscorum

Frondosorum omnium hucusque Cognitorum 2: 609 ( Müller 1851). – Cynodontium virens (Hedw.) Schimp., Corollarium Bryologiae Europaeae : 12 ( Schimper 1856). – Type: no potential type material is extant in G (cf., Frahm et al. 1998; http://www.ville-ge.ch/musinfo/bd/cjb/hedwig/; accessed 4 Feb. 2016), and the typification will be dealt with separately (Hedenäs & Ochyra in prep.).

Dicranum virens var. serratum Bruch & Schimp., Bryologia Europaea 1: 119. 49g (fasc. 37–40. Mon. 13. 3g) ( Bruch & Schimper 1847). – Cynodontium virens var. serratum (Bruch & Schimp.) Schimp., Corollarium Bryologiae Europaeae : 12 ( Schimper 1856). – Oncophorus virens var. serratus (Bruch & Schimp.) Braithw., The British Moss-Flora 1: 116 ( Braithwaite 1883). – Type: “secus rivulos” (BM, n.v.; cf., below).

Aongstroemia curvicaulis Müll.Hal., Nuovo Giornale Botanico Italiano , n.s. 5 (2): 169 ( Müller 1898). – Cynodontium curvicaule (Müll.Hal.) Paris , Index Bryologicus Supplementum Primum 111 ( Paris 1900). – Oncophorus curvicaulis (Müll.Hal.) Broth., Die Natürlichen Pflanzenfamilien 1 (3): 319 ( Brotherus 1901). – Type: “Bryotheca E. Levier. Oncophorus curvicaulis C. Müll. , c.fr., Nuovo Giornale italiano 1898, p. 169 (sub. Angstroemia), China interior, provincia Schen-si sept., in monte Thae-peisan, Aug. 1896, legit Rev. Jos. Giraldi, determ. Prof. C. Müller sub. No. 1969” (lecto-: BM-000517729!, designated here).

Cynodontium bicolor Paris , Index Bryologicus Supplementum Primum : 111 ( Paris 1900) ( Aongstroemia bicolor Müll.Hal., Nuovo Giornale Botanico Italiano , n.s. 5: 170 ( Müller 1898), nom. illeg.; later homonym). – Oncophorus bicolor (Paris) Broth., Die Natürlichen Pflanzenfamilien 1 (3): 319 ( Brotherus 1901). – Type: “Bryotheca E. Levier. Oncophorus bicolor (C. Müll. sub Angstroemia, in N. Giorn. bot. ital. 1898, p. 170) Broth., China interior, provinc. SchenSi sept., in monte Tui-kio-san, 21 Sept. 1896, legit. Rev. Jos. Giraldi, determ. Dr. C. Müller n. 1970” (lecto-: BM-000517728!, designated here).

Description

Plants up to 8 cm high, usually in loose tufts, green or yellow-green. Stem with large central strand, a cortex plus epidermis of 1–2 layers of incrassate cells, epidermis not differentiated as a hyalodermis; axillary hairs with 2–4-celled, hyaline upper portion, 10–11 µm wide, basal 1–2 cells rectangular, hyaline; rhizoids strongly branched, red-brown, smooth, in leaf axils. Leaves 2.1–4.2 × 0.6–1.0 mm, when moist from sheathing base patent to spreading, straight or screwed, when dry above sheathing base erect and tightly incurved to spreading, above strongly twisted, from ovate or rounded oblong base with narrowly triangular acumen, apex acuminate to longly acuminate; leaf margin at least partly distinctly recurved in lower leaf, below entire, upper margin in all or many leaves regularly to irregularly dentate or coarsely and somewhat irregularly denticulate, sometimes only close to leaf apex but mostly in at least some leaves down to mid-leaf or almost so, teeth single or double, mostly sharp and when strong often directed forwards, margin varying from unistratose to bistratose; costa 83–120 µm wide near base, with dorsal and ventral epidermis, one layer of large guide cells, 1(–2) layers of ventral stereids and 2–3 layers of dorsal stereids; lamina cells in acumen incrassate, 6–30 × 6–18 µm, 0.5–3.3 times as long as wide, in mid-leaf incrassate, 6–33 × 6–15 µm, 0.6–3.8(–4.2) times as long as wide, and in sheathing lamina incrassate and slightly porose, 20–109 × 5–19 µm, 1.6–15.8 times as long as wide, transition between mid-leaf and basal cells relatively sudden, due to relatively short upper lamina cells and relatively long basal cells; alar cells differentiated, rectangular, slightly to strongly inflated and forming a diffusely delimited group of 3–4 cells wide and 2–4(–5) cells long, partly bistratose, decurrent. Perigonia lateral on stem, not stalked, antheridia protected by oblong perigonial leaves with “cut-off” or acute apex. Inner perichaetial leaves 3.27–6.18 mm long, lower 29–50% oblong and broadly sheathing, above suddenly narrowed to long, narrow acumen. Seta tall, 12–29 mm; capsule cylindric or shortly so, curved or slightly curved, with distinct struma, 0.9–1.5 × 0.5–0.6 mm, 1.6–2.9 times as long as broad, more or less orthogonal to homotropus; exothecial cells incrassate or longitudinally incrassate, slightly collenchymatous or not; stomata ovate-pored, surrounded by radially arranged cells, near base of capsule; peristome red, teeth cleft or perforated to one-third or further down, with longitudinal rows of pits on outside; spores 23–38 µm, very finely rough.

Remarks

This species is on the average weaker than O. integerrimus sp. nov. In addition, it differs by its usually strongly dentate leaf margins and in that dry leaves are more tightly incurved. Plants from high elevations, which can be molecularly differentiated from lowland ones, are often relatively small. However, neither this nor other morphological features consistently distinguish plants from different elevations.

Habitat and distribution in Scandinavia

Oncophorus virens occurs on rocks, especially wet rocks, and on brook and lake shores ( Fig. 4 ). It is the only member of Oncophorus that is frequent in late snow-beds, and it grows also on soil and in open wetlands. This species is frequent mainly in the mountain range and the base- or calcium-rich lowland regions of northern Sweden ( Fig. 3C ). Like O. wahlenbergii , it has only been collected a few times in the southern third of Sweden.

Nomenclatural notes

Dicranum virens var. serratum Bruch & Schimp. ( Bruch & Schimper 1847) should differ from Oncophorus virens (Hedw.) Brid. var. virens in having strongly serrate leaf margins ( Bruch et al. 1836 – 1851). However, since O. virens has serrate to strongly serrate upper leaf margins, the var. serratus belongs within this variation (cf., Ignatov & Afonina 1992; Newmaster 2007). The types of Aongstroemia curvicaulis Müll.Hal. ( Müller 1898) and Cynodontium bicolor Paris (Paris 1900) also have strongly serrate leaf margins and clearly belong to O. virens as this species is understood here. The types of latter two names were checked to exclude that they belong to the next species.

Figures

Fig. 3. Geographical distributions in Scandinavia. A. Oncophorus elongatus (n = 459). B. O. wahlenbergii (n = 333). C. O. virens (n = 361). D. O. integerrimus Hedenäs sp. nov. (n = 247). The distribution maps are based on the S material for which geographical origin could be determined.

Fig. 4. Habitat preferences of Oncophorus elongatus, O. wahlenbergii, O. virens, and O. integerrimus Hedenäs sp. nov. in Scandinavia, based on label information from studied material in S.

Fig. 9. Oncophorus virens (specimen P 286; cf., Table 1). A. Stem leaves. B. Upper leaf acumen. C. Portion of leaf at widest point, showing the broadly recurved margin. D. Lower part of sheathing leaf portion, showing differentiated alar region (margin to the left).